A module declaring tools, a container, and a build on mesh-tools' runtime image is a container whose
purpose is serving tools — the pattern the node's tool runtime retires. Once node-tools is in the
catalogue, registering one is refused by name, with the record that says why; before, it is accepted
as it always was, so a mesh converts in the design's order and nothing is refused before there is
anything to move to. This is the mechanism that keeps the old pattern from returning by habit.
Judged from a repository manifest's own build.on, and for a built manifest — which carries no build
— from what its build stood on, now recorded beside the commit as part of a module's provenance.
